<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title> 标签选择器 </title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        body{
            color: #444;
        }
        a{
            color: #444;
        }
        ul{
            list-style-type: none;
        }
        .zw{
            color: red;
        }
        .da{
            font-size: 30px;
        }
        #item3{
            color: blue;
        }
        p{
            color: red;
        }
        #green{
            color: green;
        }
        .blue{
            color: blue;
        }

    </style>
</head>
<body>
    
    <div>
        <span> 你好 </span>
        <span class="zw"> 我很好 </span>
        <a href="#">百度</a>
    </div>

    <div>
        <span class="zw da"> 中午吃啥？ </span>
    </div>
    <p id="green" class="blue">段落</p>
    <ul>
        <li>元素1</li>
        <li>元素2</li>
        <li id="item3">元素3</li>
    </ul>
</body>
</html>